Highly efficient removal of bisphenol A by a novel Co-doped LaFeO3 perovskite/PMS system in salinity water

Abstract

Although it can effectively degrade refractory organic pollutants, advanced oxidation processes (AOPs) can be seriously interfered with the co-existing substance in salinity water. Herein, three-dimensional hierarchical cobalt-doped LaFeO3 perovskites (LaCo0.5Fe0.5O3) micron spheres composed of nano-rods were hydrothermally synthesized and applied to activate peroxymonosulfate (PMS) for degrading bisphenol A (BPA). Nearly 100% BPA was removed by LaCo0.5Fe0.5O3/PMS system in presence of more than 50 mM Cl− within only 2 min compared that of 30 min without Cl−, which was attributed to reactive chlorine species (RCS) including Cl• and HOCl with higher oxidation capacity. •OH and SO4•− produced by LaCo0.5Fe0.5O3 activating PMS played crucial roles as the source of RCS in LaCo0.5Fe0.5O3/Cl−/PMS system. The synergistic effect between ROS and RCS promoted by the enhanced oxygen vacancies and the efficient redox recycling of FeIII/FeII and CoIII/CoII. Other anions like SO42− and NO3− hardly affected the BPA degradation. BPA degradation efficiency was also improved either in a wide pH range or in the presence of natural organic matters in salty water. This work also demonstrated the potential application of FeCo bimetallic LaCo0.5Fe0.5O3 activating PMS system for degradation of BPA or other organic micropollutants in seawater system.